On six new species of Ixodidae, etc. 
463 
to linear arrangement as in Rhipicephalus simus ; numerous fine 
punctations at posterior end of body immediately anterior to 
festoons; cervical grooves short and deep, crescentic with convexity 
outwards ; marginal grooves well-defined, commencing a little 
distance behind the eyes and terminating at the external festoon 
on either side ; postero-median and accessory grooves shallow and 
ill-defined ; eyes large and pale. Venter yellowish-brown with 
few scattered pale hairs; genital grooves parallel anteriorly, diver- 
gent behind coxae and extending to festoons ; spiracles comma- 
Fig. 11. Rhipicentor nuttalli g , Spiracle, left. 
shaped (Fig. 11). Capitulum (Figs. 12 and 13) short ( l . l'l mm.), 
basis capituli large, with pronounced lateral angles, cornua strong, 
short and blunt ; palps short and broad, articles 2 and 3 rounded 
Figs. 12 and 13. Rhipicentor nuttalli g . Capitulum, dorsal and ventral 
aspects. 
laterally ; article 2 bears a large triangular retrograde process on 
its ventral surface which extends backwards beyond the line of 
insertion of the palp ; on its dorsal surface, a short blunt postero- 
internal process ; slight ventral retrograde tooth on article 3 ; 
hypostome slightly spatulate, dentition 3 1 3. Legs strong ; coxae 
(Fig. 14) spurred; coxa I. with two strong spurs placed close 
together, the internal pointed, the external, blunt; at the anterior 
angle a fold of chitin overlapping the trochanter; coxae II. and 
